WO2020030388A1 - Hydraulic arrangement for hybrid priority valve - Google Patents
Hydraulic arrangement for hybrid priority valve Download PDFInfo
- Publication number
- WO2020030388A1 WO2020030388A1 PCT/EP2019/069100 EP2019069100W WO2020030388A1 WO 2020030388 A1 WO2020030388 A1 WO 2020030388A1 EP 2019069100 W EP2019069100 W EP 2019069100W WO 2020030388 A1 WO2020030388 A1 WO 2020030388A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- hydraulic
- load sensing
- sensing signal
- valve
- source
- Prior art date
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Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
- B60T17/00—Component parts, details, or accessories of power brake systems not covered by groups B60T8/00, B60T13/00 or B60T15/00, or presenting other characteristic features
- B60T17/02—Arrangements of pumps or compressors, or control devices therefor
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
- B60T15/00—Construction arrangement, or operation of valves incorporated in power brake systems and not covered by groups B60T11/00 or B60T13/00
- B60T15/02—Application and release valves
- B60T15/025—Electrically controlled valves
- B60T15/028—Electrically controlled valves in hydraulic systems
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
- B62D—MOTOR VEHICLES; TRAILERS
- B62D5/00—Power-assisted or power-driven steering
- B62D5/06—Power-assisted or power-driven steering fluid, i.e. using a pressurised fluid for most or all the force required for steering a vehicle
- B62D5/07—Supply of pressurised fluid for steering also supplying other consumers ; control thereof
- B62D5/075—Supply of pressurised fluid for steering also supplying other consumers ; control thereof using priority valves
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
- B62D—MOTOR VEHICLES; TRAILERS
- B62D5/00—Power-assisted or power-driven steering
- B62D5/06—Power-assisted or power-driven steering fluid, i.e. using a pressurised fluid for most or all the force required for steering a vehicle
- B62D5/08—Power-assisted or power-driven steering fluid, i.e. using a pressurised fluid for most or all the force required for steering a vehicle characterised by type of steering valve used
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
- B62D—MOTOR VEHICLES; TRAILERS
- B62D5/00—Power-assisted or power-driven steering
- B62D5/06—Power-assisted or power-driven steering fluid, i.e. using a pressurised fluid for most or all the force required for steering a vehicle
- B62D5/09—Power-assisted or power-driven steering fluid, i.e. using a pressurised fluid for most or all the force required for steering a vehicle characterised by means for actuating valves
- B62D5/091—Hydraulic steer-by-wire systems, e.g. the valve being actuated by an electric motor
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
- F15B11/16—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors
- F15B11/161—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors with sensing of servomotor demand or load
- F15B11/162—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors with sensing of servomotor demand or load for giving priority to particular servomotors or users
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
- F15B11/16—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors
- F15B11/161—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors with sensing of servomotor demand or load
- F15B11/168—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors with sensing of servomotor demand or load with an isolator valve (duplicating valve), i.e. at least one load sense [LS] pressure is derived from a work port load sense pressure but is not a work port pressure itself
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/20—Fluid pressure source, e.g. accumulator or variable axial piston pump
- F15B2211/205—Systems with pumps
- F15B2211/2053—Type of pump
- F15B2211/20546—Type of pump variable capacity
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/60—Circuit components or control therefor
- F15B2211/605—Load sensing circuits
- F15B2211/6051—Load sensing circuits having valve means between output member and the load sensing circuit
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/60—Circuit components or control therefor
- F15B2211/605—Load sensing circuits
- F15B2211/6051—Load sensing circuits having valve means between output member and the load sensing circuit
- F15B2211/6054—Load sensing circuits having valve means between output member and the load sensing circuit using shuttle valves
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/60—Circuit components or control therefor
- F15B2211/605—Load sensing circuits
- F15B2211/6058—Load sensing circuits with isolator valves
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/60—Circuit components or control therefor
- F15B2211/65—Methods of control of the load sensing pressure
- F15B2211/651—Methods of control of the load sensing pressure characterised by the way the load pressure is communicated to the load sensing circuit
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/70—Output members, e.g. hydraulic motors or cylinders or control therefor
- F15B2211/78—Control of multiple output members
- F15B2211/781—Control of multiple output members one or more output members having priority
Definitions
- the present invention concerns a hydraulic arrangement for a work vehicle, in particular a hydraulic arrangement comprising a hybrid priority valve for a work vehicle, such as an agricultural vehicle.
- Work vehicles uses a fluid in pressure, e.g. oil, to operate a plurality of elements of the vehicles, such as transmission, steering, brakes and auxiliary valves.
- a fluid in pressure e.g. oil
- a source of such fluid in pressure e.g. a pump, configured to supply the fluid into a distribution circuit configured to distribute the fluid in pressure among the aforementioned elements in function of their hydraulic load.
- a known distribution circuit 1' for a work vehicle comprises a source of fluid 2' directly fluidly connected to a steering unit 3' of the work vehicle via a conduit 4' and fluidly connected to brake valve unit 5' and auxiliary valves unit 6' via a priority valve 1' fluidly interposed on a conduit 8'.
- Priority valve 1' may be a three ways proportional valve configured to divide the fluid coming from source 2' between brake valve unit 5' via conduit 8a' and auxiliary valves unit 5' via conduit 8b' . Such division corresponds to the five positions of the valve, i.e. a first positions in which no fluid may flow and therefore only steering unit 3' is using the fluid coming from source 2', a second and a third position in which fluid may flow to only brake valve unit 5' and steering unit 3' and a fourth and fifth position in which fluid may flow to all units 3' , 5' and 6' .
- Valve 7' is controlled hydraulically thanks to a pair of hydraulic load pressure signals acting on opposite sides of valve 7', a first signal 11' taken from conduit 8' upstream with respect to valve 7' and a second signal 12' taken as the greatest between signals coming from steering unit 3' , brake valve unit 5' , auxiliary valves unit 6' .
- Such greatest signal is chosen by selecting the greatest between a signal 12a' coming from brake valve unit 5' and a signal 12b' coming from steering unit 3' and then comparing such greatest signal with a signal 12c' coming from auxiliary valves unit 6' .
- Such comparison is made by respective shuttle valves 13' connecting signals 12a' and 12b' and the output between these latter with signal 12c' .
- valve 7' The balance between signal 11' and 12' allows valve 7' to be moved so as to be positioned in one of the above described positions. Since 11' is taken directly on conduit 8 upstream to steering unit 3' , more such signal is greater, more fluid will pass to units 5' and 6' , and, reversely, more signal 12' is greater, less fluid will pass to units 5' and 6', till such fluid will be zero.
- a signal 14' derives from signal 12' coming from shuttle valve 13' and flows to source 2 .
- Source 2 is configured to increase pressure of provided fluid according to the received load sensing signal 14' .
- source 2 may be a load sensing pump.
- valves 6' do no more provide a hydraulic load signal but an electric load signal; therefore the traditional distribution circuits are no more suitable for achieving their scope.
- steering unit 3' and valve unit 5' need to maintain hydraulic control for safety reasons, it is better not to transform all the elements of distribution circuit in electrically-controlled ones.
- An aim of the present invention is to satisfy the above mentioned needs.
- Figure 1 is a hydraulic scheme showing a distribution circuit for a work vehicle as known in the art
- Figure 2 is a hydraulic scheme showing a distribution circuit for a work vehicle according to the present invention.
- Figure 3 is the hydraulic scheme of figure 2 in a different operative condition.
- Figure 1 discloses a distribution circuit 1 for a work vehicle comprises a source of fluid 2 directly fluidly connected to a steering unit 3 of the work vehicle via a conduit 4 and fluidly connected to brake valve unit 5 and auxiliary valves unit 6 by a conduit 8 on which it is fluidly interposed a priority valve 7.
- Priority valve 7 may be a three ways - five positions proportional valve configured to divide the fluid coming from source 2 between brake valve unit 5 via conduit 8a and auxiliary valves unit 6 via conduit 8b. Such division corresponds to the five positions of the valve, i.e. a first position in which no fluid may flow and therefore only steering unit 3 is using the fluid coming from source 2, a second and a third positions in which fluid may flow to only brake valve unit 5 and steering unit 3 and a fourth and fifth position in which fluid may flow to all units 3, 5 and 6.
- Valve 7 is controlled hydraulically thanks to a pair of hydraulic load pressure signals acting on opposite sides of valve 7, a first signal 11 taken from conduit 8 upstream with respect to valve 7 and a second signal 12 taken as the greatest between signals coming from steering unit 3, brake valve unit 5, auxiliary valves unit 6.
- Such greatest signal is chosen by selecting the greatest between a signal 12a coming from brake valve unit 5 and a signal 12b coming from steering unit 3 and then comparing such greatest signal with a signal 12c coming from auxiliary valves unit 6.
- Such comparison is made by respective shuttle valves 13 connecting signals 12a and 12b and the output between these latter with signal 12c.
- a signal 14 derives from signal 12 coming from shuttle valve 13 and flows to source 2.
- source 2 is configured to increase pressure of provided fluid according to the received load sensing signal 14.
- source 2 may be a load sensing pump.
- valve 7 The balance between signal 11 and 12 allow valve 7 to be moved so as to be positioned in one of the above described positions. Since 11 is taken directly on conduit 8 upstream to steering unit 3, more such signal is greater, more fluid will pass to units 5 and 6, and, reversely, more signal 12 is greater, less fluid will pass to units 5 and 6, till such fluid will be zero.
- distribution circuit 1 comprises a conversion unit 15 configured to receive as input an electronic load sensing signal 16 representing a hydraulic load pressure of a hydraulic unit, e.g. auxiliary valve unit 6, and to produce, on the base of such electronic load sensing signal 16, an equivalent hydraulic load sensing signal 12c.
- a conversion unit 15 configured to receive as input an electronic load sensing signal 16 representing a hydraulic load pressure of a hydraulic unit, e.g. auxiliary valve unit 6, and to produce, on the base of such electronic load sensing signal 16, an equivalent hydraulic load sensing signal 12c.
- conversion unit 15 may comprise an ECU 17 electrically connected to auxiliary valve unit 6 and comprising memorizing and elaboration means configured to receive electronic load sensing signal 16 and to elaborate an output electric signal 18 based on such configured to control at least a valve 19 as described hereunder.
- conversion unit 15 comprises a pair of valves, namely a first valve 21 and a second valve 22; first valve 21 is fluidly connected to conduit 8 via a conduit 23 and to second valve 22 via a conduit 24, second valve 22 is further fluidly connected to a drain 25 via a conduit 26.
- Conversion unit 15 may further comprise a sensor electrically connected to ECU 17 and configured to control the pressure value of the equivalent hydraulic load signal 12c.
- sensor may be a valve 27, e.g. a pressure valve, fluidly interposed on conduit 24 and electrically connected to ECU 17.
- First and second valves 21, 22 are preferably ON-OFF two ways - two positions electro actuated valves, more preferably they can be proportional; advantageously such electrical actuation is given by a control electric signal 18 coming from ECU 17.
- the operation of the distribution circuit 1 according to the present invention is the following.
- valve 21 is positioned so that a part of fluid may flow from conduit 8 into conversion unit 15.
- ECU 17 of conversion unit 15 receives electronic load sensing signal 16 from auxiliary valves unit 6 and elaborate this latter so as to define an equivalent hydraulic load sensing signal 12c which should be imparted to shuttle valve 13. Once the equivalent pressure value of such signal is established, ECU 17 control opening of valves 21 and 22 so as to use flow of fluid coming from conduits 8 and 23 to obtain such pressure signal. If valves are simply ON-OFF valves, ECU 17 will manage switching timing of these latter and their frequency to achieve the target pressure. In the case valves 21 and 22 are proportional ECU 17 will manage them in proportional way to achieve target pressure, i.e. keeping valve 22 closed and partial sing opening of valve 21.
- ECU 17 receives the pressure value of such signal 12c so as to control in a closed loop manner the opening of valves 21 and 22.
- valve 21 When no electric signal 16 comes from auxiliary valves unit 6, valve 21 is closed and valve 22 is open so as allow remaining fluid in conduit 24 to flow to drain 25 via conduit
- a conversion unit 15 it is possible to convert a electric signal 16 coming from a unit of a distribution circuit 1, e.g. unit 6, to a hydraulic load sensing signal 12c suitable for being used in a standard hydraulic distribution circuit.
- conversion unit 15 may be used for the conversion of an electric signal defining a hydraulic load pressure of another unit than auxiliary valve unit 6.
- conversion unit 15 may comprise other valves 19 than valves 21 and 22, e.g. pressure reduction valves.
- module 15 may be physically integrated in valve 7.
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Transportation (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- General Engineering & Computer Science (AREA)
- Fluid-Pressure Circuits (AREA)
- Lifting Devices For Agricultural Implements (AREA)
Abstract
Hydraulic arrangement (1) for distributing a pressurised fluid coming from a source (2) of pressurised fluid among a plurality of hydraulic units (3, 5, 6) of a work vehicle, at least one (5, 6) of the other hydraulic units (3, 5, 6) providing an electronic load sensing signal (16) and at least one (3) of the units (3, 5, 6) providing a hydraulic load sensing signal (12b), the hydraulic arrangement (1) further comprising a priority valve (7) configured to divide the flow of fluid between hydraulic units (3, 5, 6), priority valve (7) and source (2) being hydraulically controlled by a first hydraulic load sensing signal (12) resulting as the greatest of a plurality of hydraulic load pressure signals (12a, 12b) taken from units (3, 5, 6), hydraulic arrangement (1) further comprising a conversion unit (15) configured to transform electronic load sensing signal (16) of at least one of the other hydraulic units (5, 6) into an equivalent hydraulic load sensing signal (12c) so as to allow the aforementioned comparison among hydraulic load pressure signals (12a, 12b) to define the first hydraulic load sensing signal (12) controlling priority valve (7) and source (2).
Description
"HYDRAULIC ARRANGEMENT FOR HYBRID PRIORITY VALVE"
TECHNICAL FIELD
The present invention concerns a hydraulic arrangement for a work vehicle, in particular a hydraulic arrangement comprising a hybrid priority valve for a work vehicle, such as an agricultural vehicle.
BACKGROUND OF THE INVENTION
Work vehicles uses a fluid in pressure, e.g. oil, to operate a plurality of elements of the vehicles, such as transmission, steering, brakes and auxiliary valves.
To this aim, it is provided a source of such fluid in pressure, e.g. a pump, configured to supply the fluid into a distribution circuit configured to distribute the fluid in pressure among the aforementioned elements in function of their hydraulic load.
As disclosed in figure 1, a known distribution circuit 1' for a work vehicle comprises a source of fluid 2' directly fluidly connected to a steering unit 3' of the work vehicle via a conduit 4' and fluidly connected to brake valve unit 5' and auxiliary valves unit 6' via a priority valve 1' fluidly interposed on a conduit 8'.
Priority valve 1' may be a three ways proportional valve configured to divide the fluid coming from source 2' between
brake valve unit 5' via conduit 8a' and auxiliary valves unit 5' via conduit 8b' . Such division corresponds to the five positions of the valve, i.e. a first positions in which no fluid may flow and therefore only steering unit 3' is using the fluid coming from source 2', a second and a third position in which fluid may flow to only brake valve unit 5' and steering unit 3' and a fourth and fifth position in which fluid may flow to all units 3' , 5' and 6' .
Valve 7' is controlled hydraulically thanks to a pair of hydraulic load pressure signals acting on opposite sides of valve 7', a first signal 11' taken from conduit 8' upstream with respect to valve 7' and a second signal 12' taken as the greatest between signals coming from steering unit 3' , brake valve unit 5' , auxiliary valves unit 6' . Such greatest signal is chosen by selecting the greatest between a signal 12a' coming from brake valve unit 5' and a signal 12b' coming from steering unit 3' and then comparing such greatest signal with a signal 12c' coming from auxiliary valves unit 6' . Such comparison is made by respective shuttle valves 13' connecting signals 12a' and 12b' and the output between these latter with signal 12c' .
The balance between signal 11' and 12' allows valve 7' to be moved so as to be positioned in one of the above described positions. Since 11' is taken directly on conduit 8 upstream to steering unit 3' , more such signal is greater,
more fluid will pass to units 5' and 6' , and, reversely, more signal 12' is greater, less fluid will pass to units 5' and 6', till such fluid will be zero.
A signal 14' derives from signal 12' coming from shuttle valve 13' and flows to source 2 . Source 2 is configured to increase pressure of provided fluid according to the received load sensing signal 14' . For example, source 2 may be a load sensing pump.
However new typologies of valves 6' do no more provide a hydraulic load signal but an electric load signal; therefore the traditional distribution circuits are no more suitable for achieving their scope.
Moreover, since steering unit 3' and valve unit 5' need to maintain hydraulic control for safety reasons, it is better not to transform all the elements of distribution circuit in electrically-controlled ones.
Therefore, in view of the above, the need is felt of a distribution circuit for distributing the fluid in pressure among hydraulic elements of a work vehicle in function of their load, which can be used also with new elements having only electric load sensing signals.
An aim of the present invention is to satisfy the above mentioned needs.
SUMMARY OF THE INVENTION
The aforementioned aim is reached by a hydraulic
arrangement as claimed in the appended set of claims.
BRIEF DESCRIPTION OF DRAWINGS
For a better understanding of the present invention, a preferred embodiment is described in the following, by way of a non-limiting example, with reference to the attached drawings wherein:
• Figure 1 is a hydraulic scheme showing a distribution circuit for a work vehicle as known in the art;
• Figure 2 is a hydraulic scheme showing a distribution circuit for a work vehicle according to the present invention; and
• Figure 3 is the hydraulic scheme of figure 2 in a different operative condition.
DETAILED DESCRIPTION OF THE INVENTION
Figure 1 discloses a distribution circuit 1 for a work vehicle comprises a source of fluid 2 directly fluidly connected to a steering unit 3 of the work vehicle via a conduit 4 and fluidly connected to brake valve unit 5 and auxiliary valves unit 6 by a conduit 8 on which it is fluidly interposed a priority valve 7.
Priority valve 7 may be a three ways - five positions proportional valve configured to divide the fluid coming from source 2 between brake valve unit 5 via conduit 8a and auxiliary valves unit 6 via conduit 8b. Such division corresponds to the five positions of the valve, i.e. a first
position in which no fluid may flow and therefore only steering unit 3 is using the fluid coming from source 2, a second and a third positions in which fluid may flow to only brake valve unit 5 and steering unit 3 and a fourth and fifth position in which fluid may flow to all units 3, 5 and 6.
Valve 7 is controlled hydraulically thanks to a pair of hydraulic load pressure signals acting on opposite sides of valve 7, a first signal 11 taken from conduit 8 upstream with respect to valve 7 and a second signal 12 taken as the greatest between signals coming from steering unit 3, brake valve unit 5, auxiliary valves unit 6. Such greatest signal is chosen by selecting the greatest between a signal 12a coming from brake valve unit 5 and a signal 12b coming from steering unit 3 and then comparing such greatest signal with a signal 12c coming from auxiliary valves unit 6. Such comparison is made by respective shuttle valves 13 connecting signals 12a and 12b and the output between these latter with signal 12c.
A signal 14 derives from signal 12 coming from shuttle valve 13 and flows to source 2. As known, source 2 is configured to increase pressure of provided fluid according to the received load sensing signal 14. For example, source 2 may be a load sensing pump.
The balance between signal 11 and 12 allow valve 7 to be moved so as to be positioned in one of the above described
positions. Since 11 is taken directly on conduit 8 upstream to steering unit 3, more such signal is greater, more fluid will pass to units 5 and 6, and, reversely, more signal 12 is greater, less fluid will pass to units 5 and 6, till such fluid will be zero.
According to the invention, distribution circuit 1 comprises a conversion unit 15 configured to receive as input an electronic load sensing signal 16 representing a hydraulic load pressure of a hydraulic unit, e.g. auxiliary valve unit 6, and to produce, on the base of such electronic load sensing signal 16, an equivalent hydraulic load sensing signal 12c.
According to a preferred embodiment of the present invention, conversion unit 15 may comprise an ECU 17 electrically connected to auxiliary valve unit 6 and comprising memorizing and elaboration means configured to receive electronic load sensing signal 16 and to elaborate an output electric signal 18 based on such configured to control at least a valve 19 as described hereunder.
According to the described example conversion unit 15 comprises a pair of valves, namely a first valve 21 and a second valve 22; first valve 21 is fluidly connected to conduit 8 via a conduit 23 and to second valve 22 via a conduit 24, second valve 22 is further fluidly connected to a drain 25 via a conduit 26.
Conversion unit 15 may further comprise a sensor electrically connected to ECU 17 and configured to control the pressure value of the equivalent hydraulic load signal 12c. Such sensor may be a valve 27, e.g. a pressure valve, fluidly interposed on conduit 24 and electrically connected to ECU 17.
First and second valves 21, 22 are preferably ON-OFF two ways - two positions electro actuated valves, more preferably they can be proportional; advantageously such electrical actuation is given by a control electric signal 18 coming from ECU 17.
The operation of the distribution circuit 1 according to the present invention is the following.
As disclosed in figure 3, valve 21 is positioned so that a part of fluid may flow from conduit 8 into conversion unit 15.
When units 3 and 5 are working, respective hydraulic load pressure signals 12a, 12b will be provided to shuttle valve 13 which will select the greatest between them; then, such signal will flow to the other shuttle valve 13 to compare with signal 12c, output of conversion unit 15. The greatest of such signals will sum with signal 14 and apply a force to valve 7 on opposite side of force applied by hydraulic load sensing signal 11, taken from conduit 8. As said above, such balance allows the movement of valve 7 which
regulates flow from source 2 to units 5' and 6' from a condition in which no fluid may flow to a condition of maximum flow.
ECU 17 of conversion unit 15 receives electronic load sensing signal 16 from auxiliary valves unit 6 and elaborate this latter so as to define an equivalent hydraulic load sensing signal 12c which should be imparted to shuttle valve 13. Once the equivalent pressure value of such signal is established, ECU 17 control opening of valves 21 and 22 so as to use flow of fluid coming from conduits 8 and 23 to obtain such pressure signal. If valves are simply ON-OFF valves, ECU 17 will manage switching timing of these latter and their frequency to achieve the target pressure. In the case valves 21 and 22 are proportional ECU 17 will manage them in proportional way to achieve target pressure, i.e. keeping valve 22 closed and partial sing opening of valve 21.
Thanks to sensor valve 27, ECU 17 receives the pressure value of such signal 12c so as to control in a closed loop manner the opening of valves 21 and 22.
When no electric signal 16 comes from auxiliary valves unit 6, valve 21 is closed and valve 22 is open so as allow remaining fluid in conduit 24 to flow to drain 25 via conduit
26.
In view of the foregoing, the advantages of the
hydraulic arrangement according to the invention are apparent .
Thanks to the presence of a conversion unit 15, it is possible to convert a electric signal 16 coming from a unit of a distribution circuit 1, e.g. unit 6, to a hydraulic load sensing signal 12c suitable for being used in a standard hydraulic distribution circuit.
Thanks to such conversion unit 15, it is therefore possible to allow the use of a known hydraulic distribution circuit with new electric-sensing units with few modifications .
Moreover, since some hydraulic signals are substituted by electrical ones, less pipes and less shuttle valves are needed. Therefore, dimensions, costs and noise due to the presence of such pipes and shuttle valves are reduced.
It is clear that modifications can be made to the described hydraulic arrangement which do not extend beyond the scope of protection defined by the claims.
For example, conversion unit 15 may be used for the conversion of an electric signal defining a hydraulic load pressure of another unit than auxiliary valve unit 6.
Moreover, conversion unit 15 may comprise other valves 19 than valves 21 and 22, e.g. pressure reduction valves.
Further, module 15 may be physically integrated in valve 7.
Claims
1.- Hydraulic arrangement (1) for distributing a fluid in pressure coming from a source (2) of fluid in pressure among a plurality of hydraulic units (3, 5, 6) of said work vehicle, at least one (5, 6) of said other hydraulic units
(3, 5, 6) providing an electronic load sensing signal (16) and at least one (3) of said unit (3, 5, 6) providing a hydraulic load sensing signal (12b), said hydraulic arrangement (1) further comprising a priority valve (7) configured to divide the flow of said fluid between said hydraulic units (3, 5, 6), said priority valve (7) and said source (2) being hydraulically controlled by a first hydraulic load sensing signal (12) resulting as the greatest of a plurality of hydraulic load pressure signals (12a, 12b) taken from said units (3, 5, 6), said hydraulic arrangement (1) further comprising a conversion unit (15) configured to transform said electronic load sensing signal (16) of said at least one of said other hydraulic units (5, 6) in an equivalent hydraulic load sensing signal (12c) so as to allow the aforementioned comparison among hydraulic load pressure signals (12a, 12b) to define said first hydraulic load sensing signal (12) controlling priority valve (7) and source (2) .
2.- Hydraulic arrangement according to claim 1, wherein said conversion unit (15) comprises an ECU (17) provided
with memorizing and elaboration means configured to receive said electronic load sensing signal (16), elaborate this latter and control on the base of such elaboration at least a valve (19) so as to generate such equivalent hydraulic load sensing signal (12c) .
3.- Hydraulic arrangement according to claim 2, wherein said conversion unit (15) comprises a pair of valves (21, 22) fluidly interposes on a conduit (23) fluidly connected to a conduit (8) fluidly connecting said source (2) to said other hydraulic units (5, 6), said ECU (17) regulating the opening of said valves (21, 22) so as to obtain the pressure value of said equivalent hydraulic load signal (12c) .
4.- Hydraulic arrangement according to claim 3, wherein said valves (21, 22) are ON-OFF two ways - two positions electro actuated valves.
5. Hydraulic arrangement according to any of claim 2 to 4, wherein said conversion module further comprises a sensor, electrically connected to said ECVU (17) and configured to detect the pressure value of said equivalent hydraulic load signal (12c) .
6. Hydraulic arrangement according to claim 5, wherein said sensor is a pressure valve (26) .
7. Hydraulic arrangement accord to any of the previous claims, wherein said unit (3) is a steering unit which is fluidly connected to said source (2) via a conduit (4), said
arrangement (1) further comprising a brake valve unit (5) and an auxiliary valve unit (6) fluidly connected to said source via a conduit (8), said priority valve (7) being fluidly interposed on conduit (8) and controlled by the balance of a second hydraulic load sensing signal (11) being directly taken on said conduit (8) and said first hydraulic load sensing signal (12) .
8. Hydraulic arrangement accord to any of the previous claims, wherein said selection of the greatest hydraulic signal (12a, 12b, 12c) is made by shuttle valves (13) .
9. Hydraulic arrangement accord to any of the previous claims, wherein said priority valve (7) is a three ways - five positions proportional valve.
10. Hydraulic arrangement accord to any of the previous claims, wherein said module (15) is physically integrated in said priority valve (7) .
11. Hydraulic arrangement accord to any of the previous claims, wherein said source (2) is fluidly connected to said shuttle valve (13) so as to receive a third load sensing signal (14) equal to said first hydraulic load sensing signal (12), said source (2) being configured to regulate the pressure fluid supplied to said plurality of units (3, 5, 6) according to said third load sensing signal (14) .
12. Hydraulic arrangement accord to claim 11, wherein said source (2) is a load sensing pump.
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP19737787.2A EP3833586B1 (en) | 2018-08-06 | 2019-07-16 | Hydraulic arrangement for hybrid priority valve |
US17/266,279 US11820445B2 (en) | 2018-08-06 | 2019-07-16 | Hydraulic arrangement for hybrid priority valve |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
IT102018000007889A IT201800007889A1 (en) | 2018-08-06 | 2018-08-06 | HYDRAULIC ARRANGEMENT FOR A HYBRID PRIORITY VALVE |
IT102018000007889 | 2018-08-06 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2020030388A1 true WO2020030388A1 (en) | 2020-02-13 |
Family
ID=63840946
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/EP2019/069100 WO2020030388A1 (en) | 2018-08-06 | 2019-07-16 | Hydraulic arrangement for hybrid priority valve |
Country Status (4)
Country | Link |
---|---|
US (1) | US11820445B2 (en) |
EP (1) | EP3833586B1 (en) |
IT (1) | IT201800007889A1 (en) |
WO (1) | WO2020030388A1 (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US10377414B2 (en) * | 2017-02-09 | 2019-08-13 | Deere & Company | Dual margin priority circuit for increased steering capacity |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4966066A (en) * | 1988-06-24 | 1990-10-30 | Mannesmann Rexroth Gmbh | Load sensing system with increasing priority in series of control valves |
DE202004010530U1 (en) * | 2004-07-06 | 2004-12-09 | Deere & Company, Moline | Hydraulic circuit with priority valve for vehicle has at least one further priority valve with which priority of only one load is regulated and that also has pressure adaptation function |
EP1911978A1 (en) * | 2006-10-12 | 2008-04-16 | CNH Italia S.p.A. | System for distributing pressurized oil in a vehicle, in particular a farm tractor. |
DE102008012399A1 (en) * | 2008-03-04 | 2009-09-10 | Still Gmbh | Hydraulic system for counterbalance fork-lift truck, has feed pipe attached at pump and staying in connection with priority valve for feeding steering device, where pressure level of fan drive corresponds to pressure level of device |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE19904616A1 (en) * | 1999-02-05 | 2000-08-10 | Mannesmann Rexroth Ag | Control arrangement for at least two hydraulic consumers and pressure differential valve therefor |
DE102010027964A1 (en) * | 2010-04-20 | 2011-10-20 | Deere & Company | Hydraulic arrangement |
US20140129035A1 (en) * | 2012-11-07 | 2014-05-08 | Caterpillar Inc. | Excess Flow Control Valve Calibration Method |
JP6831648B2 (en) * | 2016-06-20 | 2021-02-17 | 川崎重工業株式会社 | Hydraulic drive system |
-
2018
- 2018-08-06 IT IT102018000007889A patent/IT201800007889A1/en unknown
-
2019
- 2019-07-16 EP EP19737787.2A patent/EP3833586B1/en active Active
- 2019-07-16 WO PCT/EP2019/069100 patent/WO2020030388A1/en unknown
- 2019-07-16 US US17/266,279 patent/US11820445B2/en active Active
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4966066A (en) * | 1988-06-24 | 1990-10-30 | Mannesmann Rexroth Gmbh | Load sensing system with increasing priority in series of control valves |
DE202004010530U1 (en) * | 2004-07-06 | 2004-12-09 | Deere & Company, Moline | Hydraulic circuit with priority valve for vehicle has at least one further priority valve with which priority of only one load is regulated and that also has pressure adaptation function |
EP1911978A1 (en) * | 2006-10-12 | 2008-04-16 | CNH Italia S.p.A. | System for distributing pressurized oil in a vehicle, in particular a farm tractor. |
DE102008012399A1 (en) * | 2008-03-04 | 2009-09-10 | Still Gmbh | Hydraulic system for counterbalance fork-lift truck, has feed pipe attached at pump and staying in connection with priority valve for feeding steering device, where pressure level of fan drive corresponds to pressure level of device |
Also Published As
Publication number | Publication date |
---|---|
EP3833586A1 (en) | 2021-06-16 |
US11820445B2 (en) | 2023-11-21 |
EP3833586B1 (en) | 2022-06-22 |
IT201800007889A1 (en) | 2020-02-06 |
US20210300466A1 (en) | 2021-09-30 |
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